Sheridan Company purchased a new machine on October 1, 2017, at a cost of $77,980. The company estimated that the machine has a salvage value of $7,070. The machine is expected to be used for 71,200 working hours during its 7-year life Compute the depreciation expense under the straight-line method for 2017 and 2018, assuming a December 31 year-end. (Round answers to O decimal places, e.g. 5,275.) 2017 2018 The depreciation expense under the straight-line method